"We start to get worried when we realize that we're a little too comfortable," Daniel Lemieux, WJE's site manager at the monument, said Tuesday as he gazed up at the rappelling lines dangling from the tip of the 555-foot-high obelisk.

WJE specializes in difficult jobs and its dozen or so rappelling specialists have experience on other hard-to-access historic structures. But Lemieux, who has rappelling experience, is quick to acknowledge that the company has "never done it on anything quite this iconic."

"It sounds a bit like mixing business and pleasure, but a lot of these engineers doing this kind of work are also interested in rock climbing," he said.

In fact, the equipment being used is no different than you might see an experienced climber using on a sheer rock wall.

Two of the five engineers at the Washington Monument have worked on the Put-in-Bay memorial, which commemorates Commodore Oliver Hazard Perry's victory over a British fleet on Lake Erie in 1813. Although not as high as the Washington Monument, in some ways, the Put-in-Bay memorial is more difficult to work on, said Lemieux.

Because of a large, square, viewing platform at the top of the monument, the rappellers come down much further off the face, he said. By contrast, the smooth faces of the Washington Monument are "cleaner and easier," to work off of, he added.

One of the biggest problems is that the original designers of these structures (architect Robert Mills, in the case of the Washington Monument), typically did not plan for future repairs.

"Access was just not part of the thinking process," Hunderman said. "As a consequence, these structures can be very expensive to maintain or repair."

The rappelling procedure works well for assessing the structure, but it isn't very good for anything but the most minor repair. That means that some sort of scaffolding, perhaps an abbreviated version of what surrounded the monument when it was repaired in 1999 and 2000, will have to be put in place for this work, Lemieux said.

But for the next few days, the team will be taking notes and deciding how to proceed. That will likely mean something temporary to keep more water from getting in and damaging the steel structures inside, or possibly lead to a freeze-thaw cycle over the winter that could cause additional damage.

"First we have to figure out the extent of damage and then go through our findings. That's when we'll come up with whatever temporary fixes we need to make," Lemieux said.